Power supply system, power management apparatus, power management method, and power management program

ABSTRACT

To ensure the electricity storage amount of a power storage device in preparation for the peak period of power consumption when supplying power to a plurality of devices, a power management apparatus includes a controller that controls the plurality of devices that receive a distribution of total power supplied from the power storage device and another power supply, an acquirer that acquires the remaining electric energy of the power storage device, and a determiner that determines whether the remaining electric energy of the power storage device is not more than a first predetermined value. If the remaining electric energy of the power storage device is not more than the first predetermined value, the controller controls the plurality of devices such that the power from the other power supply is distributed to the power storage device.

TECHNICAL FIELD

The present invention relates to a power supply system, a powermanagement apparatus, a power management method, and a power managementprogram.

BACKGROUND ART

In the above technical field, patent literature 1 discloses a techniqueof supplying power supplied from a power supply unit and a secondarybattery to a device main body. Patent literature 2 discloses a techniqueof performing power supply switching control for a plurality of targetsin accordance with a demand.

CITATION LIST Patent Literature

Patent literature 1: Japanese Patent Laid-Open No. 2011-223786

Patent literature 2: Japanese Patent Laid-Open No. 2006-158146

SUMMARY OF THE INVENTION Technical Problem

In the techniques described in the above literatures, however, whensupplying power to a plurality of devices, it is impossible to ensurethe electricity storage amount of a power storage device in preparationfor the peak period of power consumption.

The present invention enables to provide a technique of solving theabove-described problem.

Solution to Problem

One aspect of the present invention provides a power managementapparatus comprising:

a controller that controls a plurality of devices that receive adistribution of total power supplied from a power storage device andanother power supply;

an acquirer that acquires a remaining electric energy of the powerstorage device; and

a determiner that determines whether the remaining electric energy ofthe power storage device is not more than a first predetermined value,

wherein if the remaining electric energy of the power storage device isnot more than the first predetermined value, the controller controls theplurality of devices such that the power from the other power supply isdistributed to the power storage device.

Another aspect of the present invention provides a power managementmethod of a system including a plurality of devices, a power storagedevice, and another power supply, comprising:

acquiring a remaining electric energy of the power storage device;

determining whether the remaining electric energy of the power storagedevice is not more than a first predetermined value; and

controlling the plurality of devices such that the power from the otherpower supply is distributed to the power storage device if the remainingelectric energy of the power storage device is not more than the firstpredetermined value.

Still other aspect of the present invention provides a power managementprogram for causing a computer to execute a method of managing power ofa system including a plurality of devices, a power storage device, andanother power supply, the method comprising:

acquiring a remaining electric energy of the power storage device:

determining whether the remaining electric energy of the power storagedevice is not more than a first predetermined value; and

controlling the plurality of devices such that the power from the otherpower supply is distributed to the power storage device if the remainingelectric energy of the power storage device is not more than the firstpredetermined value.

Still other aspect of the present invention provides a system includinga power storage device and another power supply, which supply power to aplurality of devices, comprising:

an acquirer that acquires a remaining electric energy of the powerstorage device;

a determiner that determines whether the remaining electric energy ofthe power storage device is not more than a first predetermined value;and

a controller that controls the plurality of devices such that the powerfrom the other power supply is distributed to the power storage deviceif the remaining electric energy of the power storage device is not morethan the first predetermined value.

Advantageous Effects of Invention

According to the present invention, when supplying power to a pluralityof devices, it is possible to ensure the electricity storage amount of apower storage device in preparation for the peak period of powerconsumption of the plurality of devices.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing the arrangement of a power managementapparatus according to the third embodiment of the present invention:

FIG. 2 is a block diagram showing the power-related arrangement of aserver system according to the fourth embodiment of the presentinvention;

FIG. 3 is a block diagram showing the hardware arrangement of the serversystem according to the fourth embodiment of the present invention:

FIG. 4A is a block diagram showing the hardware arrangement and softwareconfiguration in a chassis according to the fourth embodiment of thepresent invention:

FIG. 4B is a view showing exchange of power supply-related informationaccording to the fourth embodiment of the present invention;

FIG. 5 is a block diagram showing the functional arrangement of a powermanagement apparatus according to the fourth embodiment of the presentinvention:

FIG. 6 is a graph for explaining the function of the power managementapparatus according to the fourth embodiment of the present invention:

FIG. 7 is a table for explaining the function of the power managementapparatus according to the fourth embodiment of the present invention:

FIG. 8 is a table for explaining the function of the power managementapparatus according to the fourth embodiment of the present invention;

FIG. 9 is a view for explaining the function of the power managementapparatus according to the fourth embodiment of the present invention:

FIG. 10 is a flowchart for explaining the procedure of processing of thepower management apparatus according to the fourth embodiment of thepresent invention;

FIG. 11 is a block diagram showing the functional arrangement of a powermanagement apparatus according to the fifth embodiment of the presentinvention:

FIG. 12 is a view showing exchange of power supply-related informationaccording to the fifth embodiment of the present invention;

FIG. 13 is a view for explaining the function of a power managementapparatus according to the sixth embodiment of the present invention;

FIGS. 14A and 14B are flowchart for explaining the procedure ofprocessing of the power management apparatus according to the sixthembodiment of the present invention;

FIG. 15 is a view showing the display screen of the power managementapparatus according to the sixth embodiment of the present invention;

FIG. 16 is a block diagram showing the arrangement of a power managementapparatus according to the first embodiment of the present invention;

FIG. 17 is a block diagram showing the arrangement of a power managementapparatus according to the second embodiment of the present invention;and

FIG. 18 is a block diagram showing the arrangement of a power managementapparatus according to a modification of the present invention.

DESCRIPTION OF THE EMBODIMENTS

Preferred embodiments of the present invention will now be described indetail with reference to the drawings. It should be noted that therelative arrangement of the components, the numerical expressions andnumerical values set forth in these embodiments do not limit the scopeof the present invention unless it is specifically stated otherwise.

First Embodiment

A power management apparatus 1600 according to the first embodiment ofthe present invention will be described with reference to FIG. 16. Thepower management apparatus 1600 includes a controller 1601, an acquirer1602, and a determiner 1603.

The controller 1601 controls a plurality of devices 1610 that receivethe distribution of total power supplied from a power storage device1650 and another power supply 1660. The acquirer 1602 acquires theremaining electric energy of the power storage device 1650. Thedeterminer 1603 determines whether the remaining electric energy of thepower storage device 1650 is equal to or less than a first predeterminedvalue. If the remaining electric energy of the power storage device 1650is equal to or less than the first predetermined value, the controller1601 controls the plurality of devices 1610 such that the power from thepower supply 1660 is distributed to the power storage device 1650.

With the above arrangement, according to this embodiment,charging/discharging is switched in accordance with the remainingelectric energy of the power storage device. Hence, when supplying powerto the plurality of devices, it is possible to ensure the electricitystorage amount of the power storage device in preparation for the peakperiod of power consumption of the plurality of devices.

Second Embodiment

A power management apparatus 1700 according to the second embodiment ofthe present invention will be described with reference to FIG. 17. Thepower management apparatus 1700 includes a server controller 1701, anacquirer 1702, a determiner 1703, a threshold holder 1705, and a serverpriority determiner 506. The server controller 1701 controls a pluralityof servers 1710 that receive the distribution of total power suppliedfrom a battery 1750 and a power receiver 1760. The acquirer 1702acquires the remaining electric energy of the battery 1750. The acquirer1702 also acquires information of an application and the like executedin each server 1710 serving as an information processing apparatus.

The determiner 1703 refers to the threshold holder 1705, and determineswhether the remaining electric energy of the battery 1750 serving as apower storage device is equal to or less than a first predeterminedvalue.

If the remaining electric energy of the battery 1750 is equal to or lessthan the first predetermined value, the server controller 1701 startscontrolling the plurality of servers 1710 such that the power from thepower receiver 1760 is distributed to the battery 1750 with priorityover the plurality of servers 1710. More specifically, to set thebattery 1750 to a charging mode, the server controller 1701 changes theservers 1710 to a low power mode with a little power consumption. If thepower of the battery 1750 is not necessary (if surplus power exists),the battery 1750 automatically starts charging. The server controller1701 may control the battery 1750 and switch on/off of the power supplyfrom the power receiver 1760 (dotted arrow 1770 in FIG. 17)

The determiner 1703 refers to the threshold holder 1705, and determineswhether the remaining electric energy of the battery 1750 has exceeded asecond predetermined value larger than the first predetermined value.

The server controller 1701 controls the plurality of servers 1710 suchthat the power from the power receiver 1760 is distributed to thebattery 1750 with priority over the plurality of servers 1710 until theremaining electric energy of the battery 1750 exceeds the secondpredetermined value larger than the first predetermined value. That is,if the remaining electric energy of the battery 1750 exceeds the secondpredetermined value, the server controller 1701 controls the pluralityof servers 1710 such that the power from the power receiver 1760 isdistributed to the second power value holder servers 1710 with priorityover the battery 1750. The control states of the plurality of servers1710 can be confirmed on the console screen of a display provided on theserver controller 1701. Using the console screen, the user may turnon/off the battery charging priority function, display a server state,select a server, or confirm an alarm in case of battery level loweringor power oversupply.

The server controller 1701 dynamically changes the second predeterminedvalue in accordance with the states of the plurality of servers 1710. Inparticular, the server controller 1701 counts the number of servers 1710that are operating, and determines the second predetermined value basedon the number. That is, when the number increases, the server controller1701 increases the second predetermined value. Alternatively, the servercontroller 1701 may increase the second predetermined value when thecalculation amount or the number of virtual machines of the plurality ofservers 1710 increases.

In addition, the server controller 1701 may control the plurality ofservers 1710 such that charging of the battery 1750 to a predeterminedelectric energy is completed within a predetermined time by distributingpower from the power receiver 1760 to the battery 1750 with priorityover the servers 1710.

To enable power distribution to the battery 1750, the server controller1701 reduces the power consumption of a predetermined server included inthe plurality of servers 1710. Especially, each server 1710 can bedriven in at least two driving modes including a high power mode (Hmode) in which the power consumption is high and a low power mode (Lmode) in which the power consumption is low. The server controller 1701determines the driving mode (H/L) of each of the plurality of servers1710. If it is necessary to reduce the power consumption of a server,the server 1710 is selectively driven in the L mode. Alternatively, thepower consumption of the server may be reduced by changing the responsefrom that for a physical server to that for a virtual server.

The server controller 1701 selects the server 1710 based on priority andreduces the power consumption. To enable power distribution to thebattery 1750, the server controller 1701 selects the server 1710 inascending order of priority and reduces the power consumption. Theserver priority is determined by the server priority determiner 506 withreference to a server database 561.

FIG. 7 is a table for explaining the contents of the server database 561of the power management apparatus 1700 according to this embodiment. Theserver database 561 stores a maximum used electric energy, a minimumused electric energy, a requested electric energy, priority of anapplication in progress, and the like which are acquired from eachserver 1710. The server priority determiner 506 determines serverpriority in accordance with the electric energies, application, and thelike, and sets it in the server database 561. Various prioritydetermining methods are considerable. For example, an ID is physicallyadded to the hardware of each server 1710 itself, and the servers may bedivided into server groups No. 1, No. 2, and No. 3. Priority may bedetermined in accordance with a fee (SLA: Service-Level Agreement) paidby the user of each server 1710. Priority may logically be determinedbased on the type of an OS (Operating System) or the type of anexecutable application. Priority may be determined based on“self-assessment” from each server 1710. Server priority may bedetermined based on whether the load on an I/O is large. Many serversare not CPU- but I/O-bound. In a case in which the load on the I/O islarger than a predetermined value, the output of the server itselfchanges little even if the driving mode of the CPU itself is changed toL. Hence, a method is also usable in which the loads on I/Os arecompared between the servers, and a server with a large load on the I/Ois given lower priority so that the server is easily set in the L mode.

According to the above-described server database 561, for example, theserver controller 1701 selects the server 1710 based on the priority ofan application executed in each server 1710.

In addition, for example, the acquirer 1702 may acquire the actual powerconsumption of each server 1710. In this case, the server controller1701 may control to selectively reduce the power consumption for aserver with a high power consumption out of the plurality of servers1710.

If the remaining electric energy of the battery 1750 is equal to or lessthan a third predetermined value, and the power consumption of theplurality of servers 1710 is equal to or more than the suppliableelectric energy of the power receiver 1760, the server controller 1701may output an alarm or stop the operations of the plurality of servers1710.

The determiner 1703 may also determine whether the remaining electricenergy of the battery 1750 is equal to or more than a fifthpredetermined value larger than the first predetermined value. If theremaining electric energy of the battery 1750 is equal to or more thanthe fifth predetermined value larger than the predetermined value, theserver controller 1701 may distribute total power supplied from thebattery 1750 and the power receiver 1760 to the plurality of servers1710.

If the remaining electric energy of the battery 1750 is equal to or morethan the fifth predetermined value larger than the predetermined value,the server controller 1701 may distribute the power supplied from thepower receiver 1760 to the plurality of servers 1710 without dischargingor charging the battery 1750.

As described above, upon determining that the remaining electric energyof the battery 1750 is equal to or more than the fifth predeterminedvalue, the server controller 1701 may select a server with high priorityfrom the plurality of servers 1710 and increase its power consumption.

Upon determining that the remaining electric energy of the battery 1750is equal to or more than the fifth predetermined value, the servercontroller 1701 may select the server 1710 shifted to a mode with a lowpower consumption out of the plurality of servers 1710 and increase itspower consumption.

As described above, according to this embodiment, charging/dischargingis switched in accordance with the remaining electric energy of thebattery. Hence, when supplying power to the plurality of devices, it ispossible to ensure the electricity storage amount of the power storagedevice in preparation for the peak period of power consumption of theplurality of devices.

Third Embodiment

A power management apparatus 100 according to the third embodiment ofthe present invention will be described with reference to FIG. 1. Thepower management apparatus 100 includes a receiver 101, a calculator102, a first power value holder 103, a second power value holder 104,and a controller 105.

The receiver 101 receives power request information about a requestedelectric energy from each of a plurality of information processingapparatuses 110 and 120. The calculator 102 calculates a total requestedelectric energy requested by the plurality of information processingapparatuses 110 and 120 based on the power request information. Thefirst power value holder 103 holds a first suppliable power value from afirst power source 150 capable of supplying power to the plurality ofinformation processing apparatuses 110 and 120. The second power valueholder 104 holds a second suppliable power value from a second powersource 160 capable of supplying power to the plurality of informationprocessing apparatuses 110 and 120. The controller 105 controls theplurality of information processing apparatuses 110 and 120 based on thetotal requested electric energy, the first suppliable power value, andthe second suppliable power value.

According to the above-described arrangement, the information processingapparatuses are controlled in consideration of suppliable power and therequest of each information processing apparatus. It is thereforepossible to supply power to the plurality of information processingapparatuses 110 while considering balance.

Fourth Embodiment

A power management apparatus according to the fourth embodiment of thepresent invention will be described next with reference to FIGS. 2 to10. FIG. 2 is a block diagram showing the power-related arrangement of aserver system as an example of an information processing systemincluding the power management apparatus.

Referring to FIG. 2, in a rack 250 that stores a plurality of servers, apower module 220 and a power management apparatus 200 are prepared foreach region 251 that is a predetermined physical region. The powermodule 220 includes a power receiver 221 that receives system power froma power company and supplies the power to servers in the rack 250, and abattery 222 that stores power supplied from the power receiver 221. Thebattery 222 has performance that changes between the regions 251, and amaximum electricity storage amount according to power requested in thecorresponding region 251. If a surplus exists in the power supplied fromthe power receiver 221 to the region 251, the surplus power can be usedto store electricity in the battery 222.

The power management apparatus 200 monitors the power receiver 221 andthe battery 222 in the corresponding power module 220, and controls eachserver in accordance with their suppliable power values. FIG. 2illustrates the power management apparatuses 200 as a plurality ofseparate components added to the power modules 220. However, the presentinvention is not limited to this.

FIG. 3 is a block diagram showing the hardware arrangement of the serversystem according to this embodiment. The server system rack 250 includesa rack manager 301, a plurality of chassis 360, and the plurality ofpower modules 220. The rack manager 301 includes the power managementapparatuses 200 as many as the regions 251, and manages the power in therack as a whole. The power module 220 is prepared for each region 251,and supplies power to the plurality of chassis 360 included in theregion 251. The chassis 360 incorporates a plurality of servers 361.

FIG. 4A is a block diagram showing the hardware arrangement and softwareconfiguration in the chassis according to this embodiment. The powermanagement apparatus 200 is controlled by data center managementsoftware 450. The chassis 360 includes a network switch 401, theplurality of servers 361, a chassis management module 403, fans 404, andpower supplies 405. Each server 361 includes a service processor 421called a BMC (Base board Management Controller), and a CPU 423 called anSoC (System on Chip). The CPU 423 is a CPU LSI, and has, in a singlechip, not only a CPU core but also functions such as SATA (SerialAdvanced Technology Attachment)/SAS (Serial Attached Small ComputerSystem Interface), PCIexpress (Peripheral Component InterconnectExpress), and Ethernet®, which are conventionally separate LSIs.

FIG. 4B is a view showing exchange of power supply-related informationaccording to this embodiment. The power management apparatus 200receives an input power value (the value of external power used by thepower module 220), a maximum input power value (the maximum value ofexternal power that can be provided to the region), an output powervalue (a power value provided to the region by the power module), amaximum output power value (the sum of external power and battery supplypower), and a battery level value (remaining electric energy), which areprovided by the power module 220. On the other hand, the powermanagement apparatus 200 receives, from the chassis 360, powerconsumption in the chassis 360 or power consumption of each server. Thepower management apparatus 200 then sends an H/L control instruction toeach server in the chassis 360.

FIG. 5 is a block diagram showing the functional arrangement of thepower management apparatus according to this embodiment.

A receiver 501 receives, from each of the plurality of servers 361, ademand 511 concerning an electric energy requested by each of theplurality of servers 361.

A calculator 502 calculates a total requested electric energy requestedby the plurality of servers 361 based on the demands 511. An AC supplypower holder 503 holds an AC power value supplied from the powerreceiver 221 capable of supplying power to a plurality of servers. Abattery level holder 504 holds the battery level value of the battery222 capable of supplying power to the plurality of server 361.

A server controller 505 controls the plurality of servers 361 based onthe demands 511, the AC power value, and the battery level value.Especially, each server 361 can be driven in at least two driving modesincluding a high power mode (H mode) in which the power consumption ishigh and a low power mode (L mode) in which the power consumption islow. The server controller 505 determines a driving mode (H/L) 512 ofeach of the plurality of servers.

The power management apparatus 200 includes a server priority determiner506 that determines the priority of each of the plurality of servers361. The server priority determiner 506 includes a server database 561in which the attribute of each server 361 and priority derived from itare set. If the demand 511 is smaller than the total power value of theAC power value and the battery level value, the server controller 505determines whether to use the battery 222. Upon determining to use thebattery 222, the server controller 505 drives the plurality of servers361 using both power from the power receiver 221 and power from thebattery 222. Upon determining not to use the battery 222, the servercontroller 505 controls the driving mode (H/L) 512 of each of theplurality of servers in accordance with priority such that that theplurality of servers 361 can be driven only by power from the powerreceiver 221.

Upon determining not to use the battery 222, the server controller 505controls to drive a server with low priority in a mode with a lowerpower consumption as compared to a server with high priority such thatthat the plurality of servers 361 can be driven only by power from thepower receiver 221. That is, the server with high priority is driven inthe H mode, and the server with low priority is driven in the L mode.For example, if the battery level of the battery 222 is equal to or lessthan a predetermined value, the server controller 505 controls to drivea server with low priority in a mode with a lower power consumption ascompared to a server with high priority such that that the plurality ofservers 361 can be driven only by power from the power receiver 221.

FIG. 6 is a graph for explaining the function of the power managementapparatus according to this embodiment. For example, assume that themaximum output power is 25 kw, and the input power is 20 kw. During aperiod in which the battery level is sufficient, when the output powerlowers to C kw or less, charging is performed. If the output powerexceeds 20 kw, the mode transits to a battery assist mode (a mode to usethe battery 222). On the other hand, if the battery level lowers (forexample, lowers to A % or less) due to use of the battery 222, serversother than those with high priority cannot transit to the battery assistmode. The driving modes of some servers are changed to a power savingmode as needed. If the battery level of the battery 222 further lowers(for example, lowers to B % or less), the battery assist mode is notpermitted. The servers 361 are actively set in the power saving mode,and the battery 222 is charged. The thresholds A, B. and C can be set bythe system operator.

FIG. 7 is a table for explaining the contents of the server database 561of the power management apparatus according to this embodiment. Theserver database 561 stores a maximum used electric energy, a minimumused electric energy, a requested electric energy, priority of anapplication in progress, and the like which are received from eachserver 361 as the demand 511. The server priority determiner 506determines server priority in accordance with the electric energies,application, and the like, and sets it in the server database 561.Various priority determining methods are considerable. For example, anID is physically added to the hardware of each server 361 itself, andthe servers may be divided into server groups No. 1, No. 2, and No. 3 indescending order of priority. Priority may be determined in accordancewith a fee (SLA: Service-Level Agreement) paid by the user of eachserver 361. Priority may logically be determined based on the type of anOS (Operation System) or the type of an executable application. Prioritymay be determined based on “self-assessment” from each server 361.

FIG. 8 is a table for explaining the detailed contents of prioritydetermined by the power management apparatus according to thisembodiment. In a table 801, how to drive each server 361 is determinedin accordance with situations (S1 to Sn) such as a time zone. Forexample, in the situation S1, a server A is always driven in the H mode,and a server E is always driven in the L mode. Servers B to D transitfrom the H mode to the L mode in the order of server B, server D, andserver C in accordance with the supply power value. For example, in thesituation Sn (for example, in a case of power failure), the servers A toD are driven in the L mode, and the server E is turned off (sleep).

FIG. 9 is a view for explaining the function of the power managementapparatus according to this embodiment. FIG. 9 illustrates a table 900that shows examples of server driving control in the respectivesituations. The table 900 shows a server control method in each of, forexample, 10 situations S1 to S10. A column 901 shows situation numbers.A column 902 schematically shows suppliable power (upper bar) and thedriving modes of the servers (lower bar) in each situation. An upper barin the column 902 represents the magnitudes of system power (AC) andbattery power (BATT), which can be output to the region 251 in eachsituation. On the other hand, an lower bar in the column 902 representsthe magnitudes of power consumptions of the servers 361 (here, only fourservers). The characters in the bar indicate the driving modes of theservers 361.

A column 903 shows each situation as an expression. A column 904 showsthe states of the battery and the like.

The situation S1 indicates a situation in which the total powerconsumption (necessary power) when all servers are driven in the H modedoes not exceed the supply power value (AC) of the system power. In thiscase, the battery 222 need not be used. Conversely, the servercontroller 505 uses the surplus component of the system power to chargethe battery 222.

The situation S2 indicates a situation in which the total powerconsumption when all servers are driven in the H mode exceeds the supplypower value (AC) of the system power but not the maximum suppliablepower value (AC+BATT) that is the sum of the supply power value (AC) andthe power of the battery 222. In this case, all servers may be driven inthe H mode by discharging the battery 222 to attain full assist. If theremaining power value of the battery 222 falls below a predeterminedvalue, or the reliability of the battery 222 lowers in this situation,the situation may transit to the situation S3.

The situation S3 indicates a situation in which the battery 222 cannotbe used or is not used. In this situation, the servers are sequentiallychanged to the L mode in ascending order of priority until the powerconsumption of all servers becomes equal to or less than the supplypower value (AC) of the system power (suppressed to AC). If there is asurplus of system power, the battery 222 is charged.

The situation S4 indicates a situation in which the total powerconsumption when all servers are driven in the H mode exceeds themaximum suppliable power value (AC+BATT) that is the sum of the supplypower value (AC) of the system power and the power of the battery 222.In this case, all servers cannot be driven in the H mode even bydischarging the battery 222 to attain full assist.

In this case, first, as indicated by the situation S5, the servers aresequentially changed to the L mode in ascending order of priority untilthe power consumption of all servers becomes equal to or less than themaximum suppliable power value (AC+BATT) (suppressed to AC+BATT). If theremaining power value of the battery 222 falls below a predeterminedvalue, or the reliability of the battery 222 lowers in the situation S5,the situation transits to the situation S6.

The situation S6 indicates a situation in which the battery 222 cannotbe used or is not used. In this situation, the servers are sequentiallychanged to the L mode in ascending order of priority until the powerconsumption of all servers becomes equal to or less than the supplypower value (AC) of the system power (suppressed to AC). If there is asurplus of system power, the battery 222 is charged.

The situation S7 indicates a situation in which the total powerconsumption when all servers are driven in the L mode exceeds the supplypower value (AC) of the system power but not the maximum suppliablepower value (AC+BATT) that is the sum of the supply power value (AC) andthe power of the battery 222. In this case, all servers may be driven inthe L mode by discharging the battery 222 to attain full assist. If theremaining power value of the battery 222 falls below a predeterminedvalue, or the reliability of the battery 222 lowers in this situation,the situation may transit to the situation S8.

The situation S8 indicates a situation in which the battery 222 cannotbe used or is not used. In this situation, the servers are sequentiallychanged to the sleep mode in ascending order of priority until the powerconsumption of all servers becomes equal to or less than the supplypower value (AC) of the system power (suppressed to AC). At the sametime, an alert indicating that the electric energy is short isgenerated.

The situation S9 indicates a situation in which the system power is downdue to a power failure or maintenance. If the total power consumptionwhen all servers are driven in the L mode does not exceed the suppliablepower value of the battery 222 in this situation, all the servers 361are driven in the power saving mode to gain time, an alert is generated,and recovery from the power failure is waited.

The situation S10 indicates a situation in which the system power isdown due to a power failure or maintenance. If the total powerconsumption when all servers are driven in the L mode exceeds thesuppliable power value of the battery 222 in this situation, the servers361 are sequentially shifted to the sleep mode in ascending order ofpriority. At the same time, an alert is generated, and recovery from thepower failure is waited.

Assuming that the system power is more reliable than the battery 222,FIG. 9 shows the system power on the left side and the battery on theright side on each bar graph in the column 902. However, the order maybe reversed. That is, control may be done to actively use the batteryand use the system power only when the supply power value of the batteryhas temporarily fallen below a predetermined value. In this case,control is performed to suppress power consumption to the battery powervalue by controlling the driving modes of the servers.

FIG. 10 is a flowchart for explaining the procedure of processing,complying with FIG. 9, of the power management apparatus according tothis embodiment.

First in step S1001, the server controller 505 determines whether thesum of necessary power values in a case in which all servers in a regionare driven in the H mode is equal to or less than the supply power valueAC of the system power. If the sum of necessary power values in the casein which all servers are driven in the H mode is equal to or less thanthe supply power value AC of the system power, the process advances tostep S1003, and the server controller 505 drives all servers in the highoutput mode (H mode). In step S1005, charging is performed.

In step S1001, if the sum of necessary power values in the case in whichall servers in the region are driven in the H mode is more than thesupply power value AC of the system power (situation S2 in FIG. 9), theprocess advances to step S1007. In step S1007, if the sum of the supplypower value AC of the system power and the supply power value BATT ofthe battery 222 is smaller than the sum of necessary power values in acase in which all servers in the region are driven in the L mode(situation S8), the process advances to step S1009. In step S1009, theserver controller 505 generates an alert, and then advances to stepS1011. In step S1011, the server controller 505 sequentially shifts theservers to the sleep mode in ascending order of priority until the sumof the necessary powers of all servers in the region becomes smallerthan the sum of the supply power value AC of the system power and thesupply power value BATT of the battery 222, and then advances to stepS1025.

In step S1007, if the sum of the supply power value AC of the systempower and the supply power value BATT of the battery 222 is equal to ormore than the sum of necessary power values in the case in which allservers in the region are driven in the L mode (situation S5), theprocess advances to step S1013. In step S1013, if the necessary powervalue in the case in which all servers in the region are driven in the Lmode is larger than the supply power value AC of the system power(situation S7), the process advances to step S1015. In step S1015, theserver controller 505 generates an alert to notify that “the battery 222needs to be used to drive all servers”, and advances to step S1017. Instep S1017, the server controller 505 drives all servers in the L modeusing the power of the battery 222 until it is determined in step S1007that the power of the battery 222 is short.

Next, the process advances to step S1019, the server controller 505determines whether the necessary power value in the case in which allservers are driven in the H mode is smaller than the sum of the supplypower value AC of the system power and the supply power value BATT ofthe battery 222.

If the necessary power value in the case in which all servers are drivenin the H mode is equal to or larger than the sum of the supply powervalue AC of the system power and the supply power value BATT of thebattery 222 (situation S4), the process advances to step S1021, and theserver controller 505 determines whether to use the battery 222. To usethe battery 222, the process advances to step S1023, and the servercontroller 505 sequentially switches the servers from the H mode to theL mode in ascending order of priority until the necessary power value ofall servers becomes smaller than the sum of the supply power value AC ofthe system power and the supply power value BATT of the battery 222.

Upon determining not to use the battery 222 in step S1021, the processadvances to step S1029, and the server controller 505 switches thedriving modes of the servers in the order of H→L→sleep in ascendingorder of priority until the sum of the necessary power values of allservers becomes equal to or smaller than the supply power value AC ofthe system power. The process advances to step S1031. If there is asurplus of the supply power value AC of the system power, the servercontroller 505 performs charging.

As described above, it is possible to effectively and efficiently supplypower to the server system using the system power and the battery bycontrolling the driving mode of each server in accordance with thesituation.

Fifth Embodiment

A power management apparatus according to the fifth embodiment of thepresent invention will be described next with reference to FIGS. 11 and12. FIG. 11 is a block diagram for explaining the functional arrangementof the power management apparatus according to this embodiment. Thepower management apparatus according to this embodiment is differentfrom the second embodiment in that instead of designating the drivingmode of a server, a budget concerning power is notified to a server. Therest of the components and operations is the same as in the secondembodiment. Hence, the same reference numerals denote the samecomponents and operations, and a detailed description thereof will beomitted.

FIG. 11 is a block diagram showing the functional arrangement of a powermanagement apparatus according to this embodiment. A power managementapparatus 1100 includes a server controller 1105 that determines abudget (usable maximum electric energy) 1112 of each server and notifiesit. Each server 1161 determines the driving mode by itself in accordancewith the budget 1112 received from the server controller 1105. Theserver controller 1105 calculates the upper limit value of an electricenergy usable by each server in accordance with priority determined foreach server by a server priority determiner 506. The server controller1105 notifies the plurality of servers 1161 of the upper limit values ofelectric energies usable by the plurality of servers 1161. Each server1161 operates by an electric energy equal to or less than the notifiedupper limit value.

FIG. 12 is a view showing exchange of power supply-related informationaccording to this embodiment. As shown in FIG. 12, the power managementapparatus 1100 notifies a chassis 360 of the budget 1112.

In this embodiment, the server controller 1105 determines the budget ofeach server. However, the server controller 1105 may determine thebudget of a plurality of servers (for example, servers in the chassis360). In this case, the plurality of servers share the budget. As thesharing method, for example, the plurality of servers may uniformlyshare the budget. Alternatively, a server with high priority may ensurethe budget first and return it if it is unnecessary.

According to the arrangement and operation of the above-describedembodiment, since the server driving mode is determined in accordancewith the budget, it is possible to effectively and efficiently supplypower to the server system using the system power and the battery. Thatis, it is possible to implement a power consumption much lower than aconventional average power consumption defined by the sum of maximumpower consumptions of all servers.

Sixth Embodiment

A power management apparatus according to the sixth embodiment of thepresent invention will be described next with reference to FIGS. 13 and14. FIG. 13 is a view for explaining the function of the powermanagement apparatus according to this embodiment. FIG. 13 illustrates atable 1300 that shows examples of server driving control in therespective situations. The table 1300 shows a server control method ineach of, for example, 12 situations S1 to S12. The table 1300 isdifferent from the table 900 shown in FIG. 9 in that the situations S11and S12 are added. The rest of the contents is the same as in the table900. Hence, the same reference numerals denote the same components andoperations, and a detailed description thereof will be omitted.

The situation S11 indicates a situation in which the total powerconsumption when all servers are driven in the H mode is less than thesupply power value (AC) of the system power, but there is no margin tocharge a battery 222. In this case, although the server driving requestis completely met, a request to charge the battery 222 cannot be met. Inthis embodiment, if there is a request to charge the battery 222 in thesituation S11, the situation transits to the situation S12 in which someservers are driven in the L mode. The request to charge the battery 222is assumed to exist in a case in which the remaining power value of thebattery 222 has fallen below a predetermined value.

FIGS. 14A and 14B are flowchart for explaining the procedure ofprocessing, complying with FIG. 13, of the power management apparatusaccording to this embodiment. This flowchart is different from theflowchart of FIG. 10 in that steps S1401 to S1409 are added. The rest ofthe contents is the same as in the flowchart of FIG. 10. Hence, the samereference numerals denote the same components and operations, and adetailed description thereof will be omitted.

First in step S1001, a server controller 505 determines whether the sumof necessary power values in a case in which all servers in a region aredriven in the H mode is equal to or less than a supply power value AC ofthe system power. If the sum of necessary power values in the case inwhich all servers are driven in the H mode is equal to or less than thesupply power value AC of the system power, the process advances to stepS1401, and the server controller 505 determines whether a chargingrequest exists. If a charging request exists, the process advances tostep S1403.

In step S1403, the server controller 505 switches the driving modes ofservers with low priority until a margin for charging is generated, thatis, until the power consumption of all servers decreases to C (a valueobtained by subtracting power necessary for charging from the maximumoutput power of the system power) or less in FIG. 6. More specifically,the server controller 505 repetitively determines whether there is amargin for charging while sequentially switching the driving mode of theserver from the H mode to the L mode. If there is a margin for charging,the servers are driven in the driving modes at that point of time. Ifthere is not yet a margin for charging even when all servers are drivenin the L mode, the server controller 505 repetitively determines whetherthere is a margin for charging while sequentially switching the serversto the sleep mode in ascending order of priority. If there is a marginfor charging, the process advances to step S1405 to charge the battery222.

Upon determining in step S1401 that no charging request exists, theprocess advances to step S1407, and the server controller 505 drives allservers in the H mode. In step S1409, if there is a margin for charging,charging is performed (if there is no margin for charging, charging isnot performed).

A setting to define whether to give priority to battery charging may beaccepted in advance via the control screen of the power managementapparatus as shown in FIG. 15. In this case, if priority to batterycharging is set, it is determined in step S1401 that a charging requestexists.

Alternatively, in step S1401, the server controller 505 may determinewhether a charging request exists based on the remaining power value ofthe battery 222. That is, if the remaining power value of the battery222 is smaller than a predetermined value, the server controller 505determines that the charging request of the battery 222 is intense, andgives priority to charging of the battery 222 over driving of theservers. For example, based on the minimum power value necessary todrive all servers in the L mode and a time estimated to be needed forrecovery from a power failure, the server controller 505 may determinethe remaining power value (above-described “predetermined value”) thatshould be ensured in the battery 222.

With the above-described control, in this embodiment, it is possible todrive the servers while placing focus on the electricity storage amountin the battery by driving the servers in the L mode to given priority tocharging of the battery.

Other Embodiments

Note that in the second to sixth embodiments, a server has beenexplained as an example of an information processing apparatus to whichpower is supplied. However, the present invention is not limited tothis, and an arrangement for controlling electrical devices such as astorage device, network device, PC (Personal Computer), TV set, airconditioner, and other home appliances may be employed. For example, anarrangement is considerable in which, as shown in FIG. 18, whensupplying power from a battery 1750 and a power receiver 1760 toelectrical devices, the power is supplied to the electrical device via aplurality of hubs 1810. The hubs 1810 can perform various kinds ofswitching for power supply to turn on/off a TV set, adjust thetemperature of an air conditioner or refrigerator, or adjust thebrightness of an illumination. In this case as well, a hub controller1801 controls the hubs 1810 based on the remaining electric energy ofthe battery 1750, a predetermined threshold, and priority determined byan electrical device priority determiner 1806 with reference to anelectrical device database 1861, as in the second embodiment.

In the embodiments, a system power source and a battery have beendescribed as power supply sources. However, the present invention is notlimited to this, and two power sources suffice. For example, aninformation processing apparatus may be controlled based on power fromtwo power sources including a system power source based on a fossil fueland a system power source based on renewable energy. For example, thedriving mode of an information processing apparatus may be controlled inaccordance with power values from three or more kinds of power sources.As the driving modes of a server, the H mode, L mode, and sleep modehave been exemplified. However, another mode (for example, an M mode ofan intermediate power consumption between the H mode and the L mode) maybe provided.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

The present invention is applicable to a system including a plurality ofdevices or a single apparatus. The present invention is also applicableeven when an information processing program for implementing thefunctions of the embodiments is supplied to the system or apparatusdirectly or from a remote site. Hence, the present invention alsoincorporates the program installed in a computer to implement thefunctions of the present invention by the computer, a medium storing theprogram, and a WWW (World Wide Web) server that causes a user todownload the program. Especially, the present invention incorporates atleast a non-transitory computer readable medium storing a program thatcauses a computer to execute processing steps included in theabove-described embodiments.

Other Expressions of Embodiments

Some or all of the above-described embodiments can also be described asin the following supplementary notes but are not limited to thefollowings.

(Supplementary Note 1)

There is provided a power management apparatus comprising:

a receiver that receives, from each of a plurality of informationprocessing apparatuses, power request information about an electricenergy requested by each of the plurality of information processingapparatuses;

a calculator that calculates a total requested electric energy requestedby the plurality of information processing apparatuses based on thepower request information;

a first power value holder that holds a first suppliable power valuefrom a first power source capable of supplying power to the plurality ofinformation processing apparatuses;

a second power value holder that holds a second suppliable power valuefrom a second power source capable of supplying power to the pluralityof information processing apparatuses; and

a controller that controls the plurality of information processingapparatuses based on the total requested electric energy, the firstsuppliable power value, and the second suppliable power value.

(Supplementary Note 2)

There is provided the power management apparatus according tosupplementary note 1, wherein each of the plurality of informationprocessing apparatuses can be driven in at least two driving modesincluding a high power mode in which a power consumption is high and alow power mode in which the power consumption is low, and

the controller determines the driving mode of each of the plurality ofinformation processing apparatuses.

(Supplementary Note 3)

There is provided the power management apparatus according tosupplementary note 1 or 2, wherein the controller notifies each of theplurality of information processing apparatuses of an upper limit valueof an electric energy usable by each of the plurality of informationprocessing apparatuses and controls each of the plurality of informationprocessing apparatuses by an electric energy not more than the upperlimit value.

(Supplementary Note 4)

There is provided the power management apparatus according tosupplementary note 1, wherein the first power source comprises a systempower source,

the second power source comprises a battery, and

the second power value holder comprises a unit that monitors a remainingelectric energy of the battery capable of supplying power to theplurality of information processing apparatuses.

(Supplementary Note 5)

There is provided the power management apparatus according tosupplementary note 1, further comprising a setting unit that setspriority of each of the plurality of information processing apparatuses,

wherein if the total requested electric energy is smaller than a totalpower value of the first suppliable power value and the secondsuppliable power value, the controller determines whether to use thesecond power source,

upon determining to use the second power source, the controller drivesthe plurality of information processing apparatuses using both powerfrom the first power source and power from the second power source, and

upon determining not to use the second power source, the controllercontrols the plurality of information processing apparatuses inaccordance with the priority.

(Supplementary Note 6)

There is provided the power management apparatus according tosupplementary note 5, wherein upon determining not to use the secondpower source, the controller controls the plurality of informationprocessing apparatuses in accordance with the priority such that theplurality of information processing apparatuses can be driven only bythe power from the first power source.

(Supplementary Note 7)

There is provided the power management apparatus according tosupplementary note 6, wherein the controller controls to drive aninformation processing apparatus with low priority in a mode with apower consumption lower than that of an information processing apparatuswith high priority.

(Supplementary Note 8)

There is provided the power management apparatus according to any one ofsupplementary notes 5 to 7, wherein the first power source comprises asystem power source,

the second power source comprises a battery, and

if a remaining electric energy of the battery is not more than apredetermined value, the controller controls to drive the informationprocessing apparatus with the low priority in the mode with the powerconsumption lower than that of the information processing apparatus withthe high priority such that the plurality of information processingapparatuses can be driven only by the power from the system powersource.

(Supplementary Note 9)

There is provided the power management apparatus according to any one ofsupplementary notes 5 to 8, wherein the first power source comprises asystem power source,

the second power source comprises a battery, and

if it is determined not to use the battery, and a remaining electricenergy of the battery is not more than a predetermined value, thecontroller controls to drive the information processing apparatus withthe low priority in the mode with the power consumption lower than thatof the information processing apparatus with the high priority such thatthe battery can be charged.

(Supplementary Note 10)

There is provided a power management method comprising:

receiving, from each of a plurality of information processingapparatuses, power request information about an electric energyrequested by each of the plurality of information processingapparatuses;

calculating a total requested electric energy requested by the pluralityof information processing apparatuses based on the power requestinformation; and

controlling the plurality of information processing apparatuses based ona first suppliable power value from a first power source capable ofsupplying power to the plurality of information processing apparatuses,a second suppliable power value from a second power source capable ofsupplying power to the plurality of information processing apparatuses;and the total requested electric energy.

(Supplementary Note 11)

There is provided a power management program for causing a computer toexecute a method comprising:

receiving, from each of a plurality of information processingapparatuses, power request information about an electric energyrequested by each of the plurality of information processingapparatuses:

calculating a total requested electric energy requested by the pluralityof information processing apparatuses based on the power requestinformation; and

controlling the plurality of information processing apparatuses based ona first suppliable power value from a first power source capable ofsupplying power to the plurality of information processing apparatuses,a second suppliable power value from a second power source capable ofsupplying power to the plurality of information processing apparatuses;and the total requested electric energy.

(Supplementary Note 12)

There is provided an information processing system comprising:

a plurality of information processing apparatuses;

a receiver that receives, from each of a plurality of informationprocessing apparatuses, power request information about an electricenergy requested by each of the plurality of information processingapparatuses;

a calculator that calculates a total requested electric energy requestedby the plurality of information processing apparatuses based on thepower request information;

a first power value holder that holds a first suppliable power valuefrom a first power source capable of supplying power to the plurality ofinformation processing apparatuses;

a second power value holder that holds a second suppliable power valuefrom a second power source capable of supplying power to the pluralityof information processing apparatuses; and

a controller that controls the plurality of information processingapparatuses based on the total requested electric energy, the firstsuppliable power value, and the second suppliable power value.

This application claims the benefit of Japanese Patent Application No.2013-118361 filed on Jun. 4, 2013 and Japanese Patent Application No.2013-237304 filed on Nov. 15, 2013, which are hereby incorporated byreference herein in their entirety.

1. A power management apparatus comprising: memory for storinginstructions; and a processor configured to execute the instructions to:control a plurality of devices that receive a distribution of totalpower supplied from a power storage device and another power supply;acquire a remaining electric energy of the power storage device; anddetermine whether the remaining electric energy of the power storagedevice is not more than a first value, wherein if the remaining electricenergy of the power storage device is not more than the first value,until the remaining electric energy of the power storage device becomesmore than a second value which is more than the first value, theprocessor is further configured to execute instructions to control theplurality of devices such that the power from the other power supply isdistributed to the power storage device prior to the plurality ofdevices.
 2. The power management apparatus according to claim 1, whereinif the remaining electric energy of the power storage device is not morethan the first predetermined value, said controller controls theplurality of devices such that the power from the other power supply isdistributed to the power storage device with priority over the pluralityof devices.
 3. The power management apparatus according to claim 2,wherein said controller controls the plurality of devices such that thepower from the other power supply is distributed to the power storagedevice with priority over the plurality of devices until the remainingelectric energy of the power storage device exceeds a secondpredetermined value larger than the first predetermined value.
 4. Thepower management apparatus according to claim 2, wherein said controllercontrols the plurality of devices such that charging of the powerstorage device to a predetermined electric energy is completed within apredetermined time by distributing the power from the other power supplyto the power storage device with priority over the plurality of devices.5. The power management apparatus according to claim 1, wherein saidcontroller reduces a power consumption of a predetermined deviceincluded in the plurality of devices so as to enable power distributionto the power storage device.
 6. The power management apparatus accordingto claim 5, wherein said controller selects some devices out of theplurality of devices based on the priority, and reduces the powerconsumption.
 7. The power management apparatus according to claim 5,wherein said controller selects some devices out of the plurality ofdevices in ascending order of priority, and reduces the powerconsumption so as to enable power distribution to the power storagedevice.
 8. The power management apparatus according to claim 3, whereinsaid controller selects a device based on priority of an applicationexecuted in each of the plurality of devices.
 9. The power managementapparatus according to claim 1, wherein said controller preferentiallyshifts a device that is operating in a mode with a power consumptionhigher than that of the remaining devices to a mode with a low powerconsumption, thereby reducing the power consumption.
 10. The powermanagement apparatus according to claim 3, wherein said controllerdynamically changes the second predetermined value in accordance withstates of the plurality of devices.
 11. The power management apparatusaccording to claim 10, wherein said controller increase the secondpredetermined value when the number of devices that are operatingincreases.
 12. The power management apparatus according to claim 10,wherein said controller increases the second predetermined value when acalculation amount of the plurality of devices increases.
 13. The powermanagement apparatus according to claim 1, wherein if the remainingelectric energy of the power storage device is not more than a thirdpredetermined value, and the power consumption of the plurality ofdevices is not less than a suppliable electric energy of the other powersupply, said controller outputs an alarm or stops the plurality ofdevices.
 14. The power management apparatus according to claim 1,wherein if said determiner determines that the remaining electric energyof the power storage device is not less than a fifth predetermined valuelarger than the first predetermined value, said controller distributesthe total power supplied from the power storage device and the otherpower supply to the plurality of devices.
 15. The power managementapparatus according to claim 1, wherein if said determiner determinesthat the remaining electric energy of the power storage device is notless than a fifth predetermined value larger than the firstpredetermined value, said controller distributes the power supplied fromthe other power supply to the plurality of devices without charging ordischarging the power storage device.
 16. The power management apparatusaccording to claim 14, wherein if said determiner determines that theremaining electric energy of the power storage device is not less thanthe fifth predetermined value, said controller selects a device withhigh priority from the plurality of devices and increases the powerconsumption.
 17. The power management apparatus according to claim 14,wherein if said determiner determines that the remaining electric energyof the power storage device is not less than the fifth predeterminedvalue, said controller selects a device that has shifted to a mode witha low power consumption from the plurality of devices and increases thepower consumption.
 18. The power management apparatus according to claim1, wherein each of the plurality of devices comprises an informationprocessing apparatus.
 19. A power management method of a systemincluding a plurality of devices, a power storage device, and anotherpower supply, comprising: acquiring a remaining electric energy of thepower storage device; determining whether the remaining electric energyof the power storage device is not more than a first value; andcontrolling the plurality of devices such that the power from the otherpower supply is distributed to the power storage device prior to theplurality of devices, if the remaining electric energy of the powerstorage device is not more than the first value and until the remainingelectric energy of the power storage device becomes more than a secondvalue which is more than the first value.
 20. (canceled)
 21. A powersupply system including a power storage device and another power supply,which supply power to a plurality of devices, comprising: memory forstoring instructions; and at least one processor configured to executethe instructions to: acquire a remaining electric energy of the powerstorage device; determine whether the remaining electric energy of thepower storage device is not more than a first value; and control theplurality of devices such that the power from the other power supply isdistributed to the power storage device prior to the plurality ofdevices if the remaining electric energy of the power storage devicebecomes more than a second value, which is more than the first value.